Thermal Softening Measurements of Refractory High-Entropy Alloys.

Home-built equipment will be presented able to measure the thermal expansion (with a flat indenter) and indentation depth (with a pointed indenter) up to 1100 °C. In dilatometer mode, the allotropic phase transformations can be studied. For hardness, a Rockwell-type measurement is adopted.

Prediction of the Cohesion Energy, Shear Modulus and Hardness of Single-Phase Metals and High-Entropy Alloys.

In order to facilitate the prediction of some physical properties, we propose several simple formulas based on two parameters only, the metallic valence and metallic atomic radii. Knowing the composition, for single-phase alloys, the average parameters can be calculated by the rule of mixture. The input parameters can be obtained from tabulated databases.

Estimation of Shear Modulus and Hardness of High-Entropy Alloys Made from Early Transition Metals Based on Bonding Parameters.

The relationship between the tendencies towards rigidity (measured by shear modulus, ) and hardness (measured by Vickers hardness, ) of early transition metal (ETM)-based refractory high-entropy alloys (RHEA) and bond parameters (i.e., valence electron concentration (), enthalpy of mixing (Δ)) was investigated.

Change in Magnetic Anisotropy at the Surface and in the Bulk of FINEMET Induced by Swift Heavy Ion Irradiation.

Fe transmission and conversion electron Mössbauer spectroscopy as well as XRD were used to study the effect of swift heavy ion irradiation on stress-annealed FINEMET samples with a composition of FeSiNbBCu. The XRD of the samples indicated changes neither in the crystal structure nor in the texture of irradiated ribbons as compared to those of non-irradiated ones. However, changes in the magnetic anisotropy both in the bulk as well as at the surface of the FINEMET alloy ribbons irradiated by 160 MeV Xe ions with a fluence of 10 ion cm were revealed via the decrease in relative areas of the second and fifth lines of the magnetic sextets in the corresponding Mössbauer spectra.

A Sequence of Phase Transformations and Phases in NiCoFeCrGa High Entropy Alloy.

The present investigation is directed to phase transitions in the equimolar NiCoFeCrGa high entropy alloy, which is a mixture of face-centered cubic (FCC) and body-centered cubic (BCC) crystalline phases. The microstructure of the samples was investigated by using scanning electron microscopy (SEM), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), transmission electron microscopy-based energy-dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS), as well as X-ray diffraction (XRD) measurements. Based on the phases observed in different temperature ranges, a sequence of the phase transitions can be established, showing that in a realistic process, when freely cooling the sample with the furnace from high to room temperature, a microstructure having spinodal-like decomposition can also be expected.

Thickness-dependent magneto-transport properties of topologically nontrivial DyPdBi thin films.

DyPdBi (DPB) is a topological semimetal which belongs to the rare-earth-based half-Heusler alloy family. In this work, we studied the thickness-dependent structural and magneto-transport properties of DPB thin films (20 to 60 nm) grown using pulsed laser deposition. The DPB thin films show (110) oriented growth on MgO(100) single crystal substrates.

Weak Antilocalization and Quantum Oscillations of Surface States in Topologically Nontrivial DyPdBi(110)Half Heusler alloy.

Recently, a number of ternary half-Heusler compounds have been predicted independently by several research groups as candidates for 3D topological insulators. In this work, we report the observation of a two-dimensional (2D) weak antilocalization (WAL) effect, one of the hall-marks of topological surface states, and Shubnikov-de Hass (SdH) quantum oscillations in <110> oriented DyPdBi (DPB) thin films grown on MgO (100) substrates. The films prepared by pulsed laser deposition technique under the optimized conditions, showed a textured structure with (110) planes parallel to the (100) plane of MgO.

Ab initio study of AlxMoNbTiV high-entropy alloys.

The Al(x)MoNbTiV (x = 0-1.5) high-entropy alloys (HEAs) adopt a single solid-solution phase, having the body centered cubic (bcc) crystal structure. Here we employ the ab initio exact muffin-tin orbitals method in combination with the coherent potential approximation to investigate the equilibrium volume, elastic constants, and polycrystalline elastic moduli of Al(x)MoNbTiV HEAs.

Evaluation of clipping based iterative PAPR reduction techniques for FBMC systems.

This paper investigates filter bankmulticarrier (FBMC), a multicarrier modulation technique exhibiting an extremely low adjacent channel leakage ratio (ACLR) compared to conventional orthogonal frequency division multiplexing (OFDM) technique. The low ACLR of the transmitted FBMC signal makes it especially favorable in cognitive radio applications, where strict requirements are posed on out-of-band radiation. Large dynamic range resulting in high peak-to-average power ratio (PAPR) is characteristic of all sorts of multicarrier signals.

Serological and DNA-based evaluation of Chlamydia pneumoniae infection in inflammatory bowel disease.

Objectives: Chlamydia has been associated with autoimmune diseases, but a link between chlamydial infection and the aetiopathogenesis of inflammatory bowel disease (IBD) remains controversial. In this study we assessed the relationship between chlamydial infection and IBD, as evidenced by serological measurement and DNA analysis of mucosal biopsy specimens.

Patients And Methods: The sera of 78 patients with Crohn's disease (CD), 24 patients with ulcerative colitis (UC), 73 healthy family members, and 20 healthy controls were tested for anti-C.

[Laparoscopic colon operations for endoscopically unremovable polyps and tumors].

The use of laparoscopy in colorectal surgery is expanding. Minimally invasive surgery of benign lesions is widely accepted and can be performed with good results even during the learning curve. After gaining adequate expertise one can remove polyps which can not be treated with a colonoscope and early colonic carcinomas.

[Changing trends in breast surgery over a five year period (1998-2002)--a retrospective analysis].

Today's development in breast cancer surgery are characterized by the principle of the smallest necessary intervention in contrast with the radicality of the past. To achieve this goal the primary and crucial task is the recognition of early (stage I or II) breast cancer. The National Screening Program started 2002 provides ideal conditions.